Most people don't plan to take a dip when it's minus 23C.
But Australian researchers working in Antarctica are preparing to take the plunge for the winter solstice.
"When it's minus 23 degrees on the ice, and about minus 1.5 degrees in the water, and you strip down to your budgie smugglers, believe me you know you're alive," Davis research station leader Simon Goninon said.
"It's one of those things, you know it might sting a bit but it's an occasion you'll remember forever."
More than 70 expeditioners on Australia's three Antarctic research stations, and at the sub-Antarctic Macquarie Island, plan to take the icy dip on Saturday.
The winter solstice marks the shortest day of the year, when the South Pole is tilted furthest away from the sun.
"This is a turning point for our team and it also means the sun will soon return to the continent after weeks of living in twilight, when the sun has just been skimming below the horizon," Mr Goninon said.
